DESCRIPTION:
Wt. up to about 300 lbs (140 kg) in males and up to about 200 lbs (90
kg) in females. Overall tan to brown with a conspicuous white rump patch.
Males have large, curled horns whereas females
have smaller horns that do not curl back under eyes like those in males.
NATURAL HISTORY: Herbivorous. Most active morning and late afternoon/evening
(crepuscular), but may be active during the daytime (diurnal) also,
especially during winter. Bighorn Sheep have adapted to the desert in
many ways; one way is their ability to tolerate hyperthermia
(see adaptation section).
Normally their body temperature is 101 degrees, but they can tolerate
body temperatures up to 107 degrees (42 degrees C). Prefer rocky habitats
with steep slopes and cliffs to escape predators (e.g., Mountain
Lions). Males butt heads to establish mating rights, and mating
takes place during August and September. Except for bachelor males (who
form their own small groups), they live in herds led by a dominant female.

Click on thumbnails below for more images:

HORNS
VERSUS ANTLERS VERSUS PRONGHORNS

Horns
are permanent (not shed) and have a bony core and keratin sheath and are
not forked. Both sexes have horns. North American species with horns include
sheep (bighorn and Dall's), mountain goats, muskoxen, and bison. Antlers
are shed annually and are composed totally of bone and are forked. Only
males have antlers (except in caribou)(Why do you think this is? North
American species with antlers include members of the deer family (deer,
moose, elk, caribou). Pronghorns have a bony core (permanent) and a keratin
sheath (shed annually) and are forked. Both sexes have pronghorns. Only
the Pronghorn has pronghorns.